I actually ended up changing the diff fluids today. Took me an hour for the first time doing it. Front fluid color was mud looking & stinky with no metal shavings on the plugs. Rear fluid color was like Kahlua liquor and was very stinky. I will have nightmares about that smell :-) Truck seems to be a tad quieter and smoother.

Now for the t-case...Any pics you guys can show me? Any recommendations?

 

That stuff stinks huh? Wait until you have to crawl under your truck and pump it up and hope you don't spill it everywhere. My wife threw away my clothes from my last change.

I used a heavier oil because I'm at over 100k miles and my differentials at a fair amount of metal sludge on the plugs (Lucas 85w-145 but people also use 85w-125 or 80w-90). People like Mobile 1 or royal purple or amsoil and I think valvoline synthetic is good. I used the Lucas because it was on sale and I like their products but it's not synthetic.

http://www.discovery2.co.uk/transferbox_oil.html